Japanese knotweed, an extremely invasive non-native plant, has long been a scourge on landowners. It has been described by the Environment Agency as "indisputably the UK's most aggressive, destructive and invasive plant". The plant is extremely difficult to control and its deep roots can compromise the structure of buildings. Lenders have considered the presence of Japanese knotweed to be reason to refuse a mortgage.
In Williams & Waistell v Network Rail Infrastructure Limited [2017], the Claimants succeeded in a private nuisance claim against Network Rail Infrastructure Limited ("Network Rail") who had failed to control the plant on a railway embankment. The judgment will be of interest to all those who own, manage or insure significant property portfolios. It puts the onus on property owners to control invasive plants species, especially when it encroaches on or near residential homes.
The Facts
The Claimants owned adjoining bungalows in Wales whose rear walls abutted a Network Rail railway embankment. Japanese knotweed had been present on the embankment for many years.
The Claimants brought a claim in private nuisance (an unlawful interference with the use and enjoyment of land). They argued:
- That the plant had encroached on their land and that the roots had probably caused damage to their properties (although they claimed that they did not have to actually prove physical damage)
- That the presence of Japanese knotweed had unlawfully interfered with the "quiet enjoyment and amenity value" of their properties
In order to make out their claim, they would need to show that Network Rail had knowledge or constructive knowledge of the nuisance and that they had failed to take reasonable steps to prevent it.
The Claimants sought damages and an injunction requiring Network Rail to abate the nuisance and adequately treat the weed.
Judgment
The Court rejected the Claimants' first ground that encroachment per se could amount to nuisance. They upheld the long established position that physical damage had to be proved. No satisfactory evidence that physical damage had occurred was adduced by the Claimants.
The Court accepted the Claimants' second ground that the presence of the plant had interfered with their quite enjoyment and the amenity value of the property. The judge held "the amenity value of a property can include the ability to dispose of it at a proper value" and that this is "so important a part of an ordinary householder's enjoyment of his property that such an interference should be regarded as a legal nuisance".
Network Rail was deemed to have constructive knowledge of the risk posed by the plant and its potential damage. The Court was also satisfied that the interference was reasonably foreseeable and that Network Rail had failed (since 2012-13) to do all that was reasonable in the circumstances to prevent the interference (spraying the plant with herbicide was deemed inadequate).
The Court rejected Network Rail's argument that they enjoyed a prescriptive right to commit nuisance (because of the plant's presence on the land for at least 50 years) and their contention that the plant formed part of the "established character" of the locality.
The Court awarded damages to the Claimants for:
- The cost of treating the knotweed and insurance backed guarantees to eliminate it (£4,320 for each Claimant).
- The loss of amenity and interference with quiet enjoyment (£350 per annum for a four year period for each Claimant).
- The diminution in the value of the properties (£10,000 for one and £10,500 for the other Claimant).
However, the Court rejected the Claimants' application for a mandatory injunction (requiring Network Rail to remove the knotweed) considering that the grounds for granting one had not been sufficiently made out.
Comment
This judgment is significant because it has determined that the presence of Japanese knotweed can be an actionable nuisance before it has caused physical damage on neighbouring land because of its effect on the amenity value and quiet enjoyment of such land.
Property owners, managers and insurers should be aware of the potential liability they are exposed to by the presence of Japanese knotweed. Careful management, weed control and eradication programmes on any affected land will be prudent. When acquiring property, purchasers should be mindful of the presence of the plant and raise any queries with their surveyors and solicitors.
In July 2017 Network Rail, which may be facing a mass of such claims, appealed the decision. We will be closely monitoring developments.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
